Testing DNS Servers


Prior to delegating .RU, .SU, .РФ and third-level domains, the specified DNS servers may be checked for operation. Therefore, when placing a domain registration or delegation request, you should check "Run DNS servers testing".

The tests will be run for four days every three hours and will be deemed successful, if all DNS servers listed in the request meet the requirements of the Domains Registration Schedule in the appropriate TLD.

In the event of any DNS server failure (the server does not exist, out of access or fails to respond to the queries), all queries to this DNS server will stop. A repeated query to DNS server will be made at the next test session (in 3-4 hours). Upon four days' expiry, testing will be stopped. In this case:

  • Any newly registered domain will not be delegated;
  • Any attempt to modify domain records will prevent updates of the DNS servers list.
    The domain remains delegated with the former list of DNS servers.

Testing Procedure

DNS servers testing is run in the following sequence:

  1. The IP address is specified for each DNS-server in the list: first by TCP protocol, then by UDP protocol.
  2. It is necessary to verify whether the specified DNS-server name is not a synonym (CNAME).
  3. A SOA record for the particular domain name will be requested from each DNS-server, specified in the request, and from each of its IP addresses, first by UDP, then by TCP.
    SOA records in all DNS servers should be identical, the server response should be authorized.
  4. The accuracy of the contact e-mail address in the SOA record will be verified.
  5. DNS servers lists for a domain name received from all DNS servers will be compared to the list specified in the request. These lists should be identical.

Upon each test session an error message or notification on successful testing will be sent to the address specified in the "mnt-nfy" field of the form.